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Biomedical subjects

H G Tiselius

Publications and source records attributed to H G Tiselius.

At least 55 records · Page 3Linked to original sources
PubMed1988

Phosphate treatment of patients with renal calcium stone disease.

Orthophosphate was administered in a daily dose of 1.0-1.5 g to 32 patients during a median treatment period of 3.1 years. The patients were followed with repeated serum and urine analyses and KUB radiographs. Urine composition with respect to calcium oxalate supersaturation was favorably affected. There were reductions of urinary calcium (p less than 0.01) and calcium/citrate quotients (p less than 0.001). During the follow-up period 31 new stones were formed by 12 patients. When the rate of stone formation during treatment was compared with that during a period of similar length following diagnosis, there was no difference. On the other hand, 73 stones had formed during a period of similar length before the start of treatment. This demonstrates the problem concerning evaluation of medical prophylaxis. Four of 11 patients treated for a period longer than that expected for new stone formation continued to form stones. Stone formation was also recorded in 8 out of 15 patients with a shorter follow-up. Despite favorable biochemical effects the clinical result with orthophosphate treatment was disappointing, at least with the doses used in this study.

Adult↗
PubMed1988

Extracorporeal shock wave lithotripsy of proximal and distal ureteral stones.

Extracorporeal shock wave lithotripsy (ESWL) was used for treatment of 105 patients with ureteral stones. There were 77 stones in the upper part of the ureter, i.e. above the pelvic brim, and 28 in the lower part, i.e. below the sacroiliac joint. Successful fragmentation was attained in 101 (96%). In 93% of the patients with stones in the upper ureter and in 100% with stones in the lower ureter the fragments were eliminated completely. In 87% of the patients with stones in the upper ureter, a ureteral catheter was introduced under local anesthesia but without fluoroscopic control. It was thereby possible to remove 30% of the stones from the ureter to the kidney. For the remaining stones, saline was infused through the catheter during ESWL. For patients with stones in the lower part of the ureter, a ureteral catheter was passed in 79% and saline infused during treatment. Whereas some form of anesthesia was used for treatment of all upper ureteral stones, 89% of the treatments for lower ureteral stones were performed without anesthesia. Auxiliary procedures after ESWL were limited to four ureteral catheter manipulations for distal stones. Four proximal stones which remained unaffected by ESWL had to be treated by open surgery (3 stones) or percutaneous surgery (1 stone). Of 82 ureteric stones treated in situ the success fragmentation rate was 95%. The average number of ESWL sessions was 1.04 for both proximal and distal ureteral stones.

Adolescent↗
PubMed1988

Hemiacidrin: a useful component in the treatment of infectious renal stones.

Experimental irrigation of 15 infectious renal stones with hemiacidrin resulted in complete dissolution of 11 stones within 5 days. Three of the undissolved stones had a calcium oxalate (CaOx) content of more than 10%. Stones containing calcium phosphate (CaP) and magnesium ammonium phosphate (MAP) and weighing less than 500 mg were most easily dissolved. Twenty-five stones placed in 10 ml of hemiacidrin resulted in complete dissolution of 13 and partial dissolution of 11. Even this experiment showed that the CaOx content was of importance for the outcome of hemiacidrin treatment. After treatment the MAP and CaP fractions had decreased and CaOx increased. In 36 clinical irrigations of residual concrements of known chemical composition, 5 resulted in total stone dissolution and 21 in a reduced stone volume, whereas the result was inconclusive in 3. Seven stones were not affected by the treatment, these stones were usually composed of CaP and CaOx. There was a good correlation between the dissolution test and the clinical response to hemiacidrin treatment. Based on these findings it is suggested that hemiacidrin might be a useful complement to the modern techniques of stone fragmentation such as extracorporeal shock wave lithotripsy and percutaneous surgery, at least for infectious stones with a CaOx content of less than 10%.

Calcium Oxalate↗
PubMed1987

Measurement of the risk of calcium phosphate crystallization in urine.

A method is described for analysis of the risk of calcium phosphate (CaP) crystallization in urine samples. The pH required for formation of 500 crystals in the size range 3.5 to 5 micron (pHCaP) was determined in a Coulter Counter following addition of sodium hydroxide. The risk of CaP crystallization (CaP-CR) was defined as: 1/(pHCaP--5.8). CaP-CR was determined in 24 h urine collections from 25 patients with calcium stone disease and 26 normal subjects, each urine diluted to a creatinine concentration of 5 mumol per ml. The mean (+/- SD) CaP-CR was 0.71 +/- 0.18 and 0.63 +/- 0.14 respectively and did not differ significantly. This method might be useful for evaluations and follow-up of stone formers with respect to the risk of CaP precipitation and stone formation.

Calcium Phosphates↗
PubMed1987

Inhibition of calcium oxalate crystallization in urine.

Chromatographic separation of urine showed inhibition of calcium oxalate (CaOx)-crystallization among substances with both large and small molecular weights. Ultrafiltration showed that approximately 80 per cent of the inhibiting activity, as determined in 2 per cent urine, originated from substances with a molecular weight above 1,000. Dialysed urine was diluted to 7.5 mmol of creatinine per 1 and supersaturated with respect to CaOx. The rate of crystallization in these samples was slower in normal subjects than in stone formers (p less than 0.05). The inhibiting activity in diluted urine from the two groups did not differ and neither did the concentration of alcian blue precipitable polyanions. From measurements in diluted urine it was apparent that inhibition was demonstrable with a urine concentration as low as 0.3 per cent.

Calcium Oxalate↗
PubMed1987

The composition of four-hour urine samples from patients with calcium oxalate stone disease.

Urine collected during a 24-h period between 06.00 and 10.00 h from 25 patients with recurrent CaOx stone disease was analysed with respect to calcium, oxalate, magnesium, citrate and creatinine. Urinary excretion of oxalate in relation to creatinine was slightly higher in 24-h urine but the correlation between 24-h and 4-h values was good. Good correlations were also recorded for calcium and citrate, whereas a more variable result was obtained for magnesium. In terms of the risk of forming a supersaturated urine (CaOx risk index), a good correlation was observed between 24-h and 4-h urine samples, although the highest values were found in 24-h urine. As a result of a low mean urine flow between 06.00 and 10.00 h, the highest supersaturation in terms of the AP (CaOx) index was observed in these samples. When the risk of calcium oxalate crystallisation (CaOx-CR) was determined by means of the increment in oxalate concentration required for precipitation of CaOx, 7 of 11 samples had the highest values in the 4-h urine. Samples collected during a 4-h period might thus be useful in the evaluation and follow-up of CaOx stone formers and further studies will show to what extent they can replace 24-h urine collections.

Calcium↗
PubMed1987

Endocrine changes and urinary citrate excretion.

Urinary citrate affects the ion-activity products of calcium oxalate and calcium phosphate and inhibits the growth of these crystals. Women are less prone to develop calcium stones and because they also excrete more citrate than men, an effect of sex steroids on citrate excretion might be important. We therefore analysed urinary citrate and creatinine before and during treatment with estrogen alone or together with medroxyprogesterone acetate in 29 postmenopausal women and at different gestational ages in 19 pregnant women. Urinary citrate and creatinine was also determined before and after orchidectomy in ten men with carcinoma of the prostate. The excretion of citrate and the ratios between citrate and creatinine were not significantly altered by pregnancy or orchidectomy. Neither did treatment with estrogen or estrogen/medroxyprogesterone acetate affect these variables. We were unable to explain the difference in citrate excretion between men and women by effects of sex steroids.

Adult↗
PubMed1987

A method for description and classification of patients with urolithiasis.

A method for description and classification of patients with renal stone disease is presented. The system which has been used in the clinical routine during several years, summarizes information on the current stone situation, previous surgical procedures, the presence of anatomical abnormalities and the result of stone analysis. This system of classification provides a basis for surgical and medical decisions.

Humans↗
PubMed1987

Urine composition and stone formation during treatment with acetazolamide.

Twelve patients who formed renal stones during acetazolamide treatment for glaucoma were studied. Calcium phosphate was the dominating component in the stones. Long term treatment with acetazolamide decreased urinary citrate markedly, which will result in an increased ion-activity product of calcium phosphate and a decreased inhibiting property of urine on calcium phosphate crystallization. The treatment also increased urinary oxalate which together with a low citrate might increase the risk of calcium oxalate crystallization. However, an estimate of the ion-activity product of calcium oxalate in urine (AP [CaOx]-index) was unaffected by the treatment and calcium oxalate was a minor component of the stones.

Acetazolamide↗
PubMed1987

Hyperoxaluria.

Urinary oxalate is considered to play a crucial role in the formation of renal stones. In this respect hyperoxaluria constitutes a special problem, mainly because of the specific physicochemical properties of oxalate. The appropriate management of patients with this disorder must be based on a thorough understanding of the absorption, metabolism and excretion of oxalate. Different reasons for high oxalate excretion as well as analytical problems and our current therapeutic possibilities are covered in this review.

Humans↗
PubMed1986

Biochemical risk factors in patients with renal staghorn stone disease.

Thirty-three patients operated on for renal staghorn calculous disease were studied retrospectively with respect to urine and stone composition, bacteriuria, and abnormalities of the urinary tract. Calcium phosphate was the most common stone constituent, present in 30 of 31 concrements. Twenty-one of these stones also contained magnesium ammonium phosphate, despite the fact that only 10 patients had presented evidence of urinary tract infection during the initial period of the disease. Twenty-four-hour urine composition was normal in only 3 patients. In 59 per cent an increased CaOx risk index was observed suggesting that CaOx risk factors might contribute to the development of staghorn concrements. A metabolic evaluation of staghorn stone formers appears to be of importance for design of the postoperative treatment.

Adolescent↗
PubMed1986

Clinical results of allopurinol treatment in prevention of calcium oxalate stone formation.

Allopurinol in a daily dose of 300 mg. was administered to 99 patients with calcium oxalate stone disease. Treatment was started irrespective of urine composition and was continued for up to 8 years. Only 43 per cent of the patients treated for 5 or more years remained free of further stone formation, a result not better than observations in untreated stone patients. When patients were subgrouped with respect to recurrent or nonrecurrent stone formation during treatment, the former group, besides being followed for longer intervals than the latter group, had a urine composition suggesting a higher crystallization risk. We concluded that with the possible exception of hyperuricosuria or hyperuricemia the indication for allopurinol treatment of recurrent calcium oxalate stone disease is weak. The results also demonstrate clearly the problems combined with evaluation of prophylactic medical therapy in patients with calcium stones. The necessity of long-term followup and analysis of the biochemical risk situation is emphasized.

Allopurinol↗
PubMed1986

The effect of pH on the risk of calcium oxalate crystallization in urine.

The risk of calcium oxalate (CaOx) crystallization at different pH levels was determined in urine from recurrent CaOx-stone formers and normal subjects. The highest crystallization risk was observed between pH 4.5 and 5.5. In the pH range 6.5-7.5, there was a marked increase in crystallization of calcium phosphate (CaP). The results suggest the beneficial effect of moderate alkalinization in terms of a reduced CaOx crystallization. Reduced CaOx crystallization occurs at the expense of an increased formation of CaP crystals. Whether this increases the risk of CaP-stone formation is not known, but the CaP crystals were usually small, at least below pH 7.5.

Calcium↗
PubMed1986

An estimate of the ion-activity product of magnesium ammonium phosphate in urine.

Based on the analysis of magnesium (Mg), ammonium (NH4), phosphate (P), urine pH, and urine volume (V), a simplified estimate (AP[MAP] index) of the ion-activity product of magnesium ammonium phosphate (AP MAP) was derived: (Formula: see text). The factor A varies according to the collection period. In 4-hour urine samples more than half of the patients with staghorn calculi had values above 5 in contrast to normal subjects and calcium oxalate stone formers in whom lower values apparently were the rule. The AP(MAP) index might be of value in the evaluation and follow-up of patients with staghorn calculous disease.

Calcium Oxalate↗